Hello guys.
I have a tank of 2.5 meters of high, in the facility where i work.
An LVDT. Transmitter to measure the level of liquid inside the tank.
When the tank is full of liquid, the displacer would be at the highest position, And the transmitter give me 20 ma as 100% of level.
At that position i wonder why the LVDT is not also 2.5 m too.
Because from outside the tank at the top where normally it's located.
Or is there a possibility of the LVDT is not the same length of the high of tank?
What is the role of the spring? Does it have to do with my question?

 

Displacer type level transmitters with LVDT sensing element that I am familiar with have an LVDT movement range of about one inch.
The supported liquid level range typically depends on the length of the displacer. For example, if the displacer is 20 inches long, liquid levels of 0 to 20 inches can be measured, but the LVDT core will only move 1 inch over that range.
The spring suppresses effects of turbulence to produce stable output signal.

 

Now i understand, and it's clear for me, thank you very much chris